WASHINGTON — For Susan Bro, mother of the woman killed at a rally organized by white supremacists, the president of the United States can offer no healing words.

She says the White House repeatedly tried to reach out to her on Wednesday, the day of Heather Heyer's funeral. But she's since watched President Donald Trump lay blame for the Charlottesville violence on "both sides."

"You can't wash this one away by shaking my hand and saying 'I'm sorry,'" she said in a television interview on Friday.

In moments like this, of national crisis or tragedy, presidents typically shed their political skin, at least briefly. They use the broad appeal of the presidency to unite and soothe, urging citizens to remember their humanity, their common bonds as Americans.

George W. Bush famously climbed atop a pile of rubble in New York City to speak through a bullhorn after the Sept. 11 terrorist attacks. Barack Obama sang "Amazing Grace" during the eulogy for a black pastor killed in a racially motivated shooting in Charleston, South Carolina.

Like no other president in recent history, Trump has struggled with this part of his duties.

He talks about politics at odd moments — reminding Boy Scouts and Coast Guard graduates alike that he won the election and the media are out to get him — and has continued speaking to his core supporters with less effort to appeal to the rest of the country. The harsh language that turned off those who voted against him last year hasn't abated during his seven months in the White House, part of the reason his approval rating is locked in the 30s.

Trump's words on Charlottesville "caused racists to rejoice, minorities to weep, and the vast heart of America to mourn," the 2012 GOP presidential nominee Mitt Romney wrote on Facebook on Friday.

With CEOs fleeing after Trump's comments, he disbanded White House business councils. The entire membership of the President's Committee on the Arts and Humanities resigned. On Friday, numerous charities were following the Cleveland Clinic in pulling business from his private Mar-a-Lago resort in Florida. And some Republican lawmakers who had hoped to work with Trump lambasted him — Sen. Bob Corker of Tennessee said Thursday the president has not shown he knows "the character of the nation."